Somewhere about 430 million years ago, a fish decided to try to go ashore, and the world has never been the same.
The question of how this happened fascinates biologists, so the discovery of these fish species with bodies suitable for land locomotion could prove useful, even if most are apparently too lazy to use the “powers” of little Ariel.
A study of the skeleton by an international team of researchers indicates that at least eleven species of fish could go ashore.
In this paper, published in the Journal of Morphology, scientists have successfully reconstructed the genealogical tree of Balitoridae (Balitoridae), a family of small fish native to South, Southeast Asia and East. This family, also known as river or torrent loaches, is currently made up of over 100 species.
These include cave fish (Cryptotora thamicola), the only living species of fish we know to land on land, in a similar way to four-limbed vertebrates. such as reptiles or amphibians.
This ability was discovered in 2016, when scientists observed that the animal can walk sequentially sideways due to its robust pelvic girdle, in a manner similar to that of a salamanders.
Through a comparative analysis of balitorid DNA, the team made an evolutionary map that allowed them to identify three dominant variants of the pelvic anatomy of this family. Specifically, they analyzed the bone structure of nearly 30 species of river lakes and established three categories of pelvic forms.
By analyzing the shape of the bone that connects the spine to the pelvic fins in some of the species tested, scientists found that ten other species share the unusually robust pelvic girdle they have. cave fish.
“The fish usually has nothing to do with the spine and the pelvic fin,” says Zachary Randall, a biologist at the Florida Museum. Ã¢ â¬ ÅObviously, we didnÃ¢ â¬ TMt believe that the cave cave was completely unique. What is really interesting about this study is that it shows in detail that robust pelvic waists are more common than we thought in the river loach family.